1. Field of the Invention
The present invention relates to a low-frequency treatment device to use in bath as in bath tub.
2. Description of the Prior Art
It is known that electric massage using low-frequency voltage accelerates the growth and regeneration of hair in the subject's skin such as the scalp, as well as promoting its metabolism. Since such electric massage requires a relative high voltage, a commercialized ac source is usually used.
Low-frequency treatment devices using commercialized ac source are not necessarily adequate because they may cause pain and/or burn when used in bath, specifically, in bath tub, for a simultaneous thermotherapy.
For these reasons, batteries are employed to power low-frequency treatment device when it is used in a bath. Conventional device has the drawbacks that it renders attainment of the desired efficacy very difficult because batteries usually provide a relatively low voltage; and that it requires an expensive voltage increasing means such as converter in case a relatively high voltage must be taken out from a battery.
Combination of low-frequency treatment with thermotherapy involves the problem that load resistance variation such as that with the distance between the electrodes or the conditions of the subject's skin renders application of a constant voltage to the subject's skin very difficult.